board has lacked a quorum of three members and has been unable to rule in hundreds of pending cases since Trump in January fired NLRB Member Gwynne Wilcox, an appointee of Democrat President Joe Biden.
It was the first time since the board was created in 1935 that a member had been removed.
The U.S. Supreme Court in May allowed Wilcox's removal pending the outcome of her legal challenge, which could set an important precedent on the president's ability to remove members of agencies designed to be independent from the White House.
The board is also facing a series of lawsuits, including cases by Amazon.com and Elon Musk's SpaceX, claiming its structure and in-house enforcement proceedings violate the U.S. Constitution.
The White House, the NLRB, Boeing, and Murphy did not immediately respond to requests for comment.
If confirmed, Mayer and Murphy will join the board's acting chair, Republican Marvin Kaplan, and Democrat David Prouty.
The NLRB hears cases involving illegal labor practices, including interference with union organizing, and decides disputes involving union elections. The board, which by tradition has no more than three members from one party, can adopt rules interpreting federal labor law but typically sets new policies through decisions in individual cases.
Without a quorum, the board cannot review decisions by the agency's administrative judges, rendering them unenforceable. Unions and worker advocates have said the hobbling of the board has made it impossible to force some employers to cease even egregious and blatant legal violations, such as refusing to bargain and firing union supporters.
A Republican majority is expected to roll back many decisions issued during the Biden administration that were seen as favoring unions and heavily criticized by business groups.